Cyanobacteria Bloom Advisory for Charles River Lifted (PRESS RELEASE)
FOR IMMEDIATE RELEASE: October 9, 2024
Contact: Stefan Geller, Charles River Watershed Association
Phone: 781-572-9341
Email: sgeller@crwa.org
BOSTON, MA – The cyanobacteria bloom advisory in the Charles River downstream of the Longfellow Bridge was lifted yesterday afternoon.
DPH collected samples in the Charles River Lower Basin on Monday, Oct. 7 at Lechmere Canal, Broad Canal and Lederman Park, and laboratory analysis showed cyanobacteria levels were below DPH’s guideline of 70,000 cells/mL at all three locations. The toxin microcystin was not detected in all three samples.
Cyanobacteria, or blue-green algae, are naturally occurring microorganisms in rivers, lakes and ponds that can potentially release harmful cyanotoxins that are particularly dangerous to children and pets. Cyanobacteria grow rapidly when bodies of water experience high phosphorus levels, hotter temperatures and stagnant conditions.
In the Charles River, cyanobacterial blooms are a symptom of excess stormwater pollution and degraded ecology. Current stormwater regulations mandate an over 50% reduction in nutrient loading from watershed communities by the year 2038. While progress has been made, this bloom highlights the work to be done and the importance of addressing municipal stormwater runoff.
DPH staff initially identified the cyanobacteria bloom last month based on a visual assessment of the river, which was corroborated by water quality data from EPA’s Charles River buoy and by sampling and microscope analysis conducted by the Charles River Watershed Association (CRWA).
For ongoing water quality updates, please visit CRWA’s flagging webpage.
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Charles River Watershed Association’s mission is to protect, restore and enhance the Charles River and its watershed through science, advocacy, and the law. CRWA develops science-based strategies to increase resilience, protect public health, and promote environmental equity as we confront a changing climate.